Post Environmental Impact Assessment and Toxicological Evaluation of MajorEmissions on Selected Fauna of the AP filling Station, University of Lagos, Lagos.

Nigeria

*Kemabonta, K.A. and Aderemi, A. ODepartment of Zoology, Faculty of Science, University of Lagos, Akoka, Lagos Nigeria

* E mail of corresponding author: kennykemabonta@unilag.edu.ng

AbstractPost environmental impact assessment of AP filling Station and the evaluation of the toxiceffects of the major emissions (petrol, kerosene and diesel) on selected fauna were investigatedat University of Lagos, Lagos. The five major plant species found around the petrol stationincluded Solanium toruum, Laportea aestnans, Commeliara Spp, Cynodon diafylon andAmaranthus spinosus while the animal species included Ariolimax columbianus, Eudriluseuginiae, Mantis religiosa, Macrotermes bellicosus and Sessarma huzardi. Heavy metals weremore concentrated in the top-soil and sediments than in plants, animals and water. Petrol wasthe most toxic, followed by kerosene and diesel. LC50 value of petrol, kerosene and diesel at96hr against earthworm were 0.949ml/L, 2.664ml/L and 6.281ml/L respectively while that formud crab were 0.275ml/L, 1.645ml/L and 5.257ml/L respectively. The LC50 value of petrol,kerosene and diesel at 24hr for termite, was 0.210ml/L, 0.222ml/L and 0.333ml/L respectively.The effect of long term exposure to petroleum product fumes by filling station attendants wasalso investigated

Key words: Termites, Mud crabs, Earthworms, Toxicity, Petrol, Diesel and Kerosene

Introduction

University of Lagos Akoka Yaba, situated at approximately 60 31’ 06’’ N and 30 23’50’’ E of the Greenwich Meridian is bounded in the North by Ilaje Eseodo, South-westby Iwaya and South-east by the Lagos Lagoon. Apart from academic activities,commercial activities that take place in University of Lagos to provide the people of thecommunity include a Shopping complex, a bookshop, a power generating facility,University press, transport area and an AP filling station. Some of these facilities,through their activities generate emissions which are not friendly to the environment.

The AP Petrol Station is powered by generators due to constant failure in the supply ofhydro-electricity. Apart from the sales of products such as petrol, kerosene, diesel andengine oil, they also engage in other activities such as food-mart, lube- bay, car wash, aswell as services and repairs of vehicles. During these activities, many wastes (effluentsor emissions) are generated , which find their way into the environment therebypolluting water, soil, air and cause harm to living things.

PAT June, 2014; 10 (1): 1-16 ISSN: 0794-5213

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Pollution can be defined as the introduction by man, waste substances or energy into theenvironment in such a concentration that lead to detrimental effects on lives andproperties (Don-Pedro, 2009). In the light of this, there is the need to carryout researchthat will assess the attendant impacts of University of Lagos AP filling station. Theobjectives of the research were to carry out a Post-Impact Assessment of University ofLagos AP Filling Station and determine the relative toxicities of the major emissions onsome of the identified ecologically important animals at the University. This willprovide a reliable reference material for those who may wish to carry out similarresearch in the nearest future and provide data for making sound judgment for futuredecisions in Environmental Protection exercises in citing such related facilities.

Materials and Methods

The Study AreaThe study area covers 1km radius of the filling station. It is characterized by four majorland use types which include: Built up areas, water bodies, Non-built up and wet lands.

The impacted study site is University of Lagos AP Filling Station and the control site iswithin a radius of 1Kilometer and had similar terrain, environmental conditions, faunaand flora with the study site (Fig. 1). There was 17 staff at the filling station whichincluded 3 management staff, 6 senior staff and 8 junior staff. Six (6) 33,000 liters tanks(Four for petrol, one for diesel and one for kerosene) were buried 12ft deep into theground. Special pumping machines with meters were constructed and attached to them.The present fuel pump technology adopted at the filling station is known as digitalreadout pump machine, control system and cash register, which shows volume, andamount or price.

Physico-Chemical Properties of Effluents/EmissionsThe color and temperature of the effluents/emissions were determined in situ at the site(field) by observation and mercury thermometer respectively, while the components ofthe effluents/ emissions such as the heavy metals and hydrocarbons were determined byanalysis in the chemistry laboratory at the Faculty of Science of the University.

Sampling Design and Procedure Adopted In Ecological SurveyThe type of sampling design adopted for the ecological study is the grid system, inwhich a grid of 12 cells were established within 1km radius of the project site, with theproject site as the center. A surveillance survey was carried out after that. The purposeof the survey is to locate, establish, mark and pick grid cells for active sampling in both

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the study and the control sites. Eight (8) sampling stations (Figure 1) (4 at the study siteand 4 at the control site) were selected for all the necessary sample collections. Landbase and water base samples, (considering the availability of all the parameters and theirproximity to both the study and the control sites) were collected. Square quadrants of1meter square (1msq) were used in the sample collection of plants and land basedanimals.The samples were collected by randomly throwing the quadrants and counting thenumber of individuals of each species of plants and animals. The unidentified specieswere taken to the laboratory for proper identification by Botanists and Zoologists atBotany and Zoology Departments respectively, of the University of Lagos.

Collection and Holding of Plant, Sediment, Soil, Animal and Water SamplesSamples collection and holding were carried out in accordance with Department ofPetroleum Resources (D.P.R) guide lines and standards. Dominant plants and animals

(i.e. whole plant and wholeanimal) were collected fromboth the affected site andthe control site for analysisof heavy metals andhydrocarbons. Moreover,surface water and top soilwere collected for analysisusing clean containers.

Thereafter, all samples werelabeled indelibly, givingdetails of sampling points,sampling stations, time ofsampling and name ofpersonnel sampling.Samples were replicatedthree times to reducesampling error.

Figure 1: Study area showing sampling locations

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RespondentsThe respondents include workers at the filling station and people living and workingwithin 1km radius of the petrol station (study site). Data were collected from therespondents by the administration of questionnaires, the content of which related totheir socio- economic and health status.

Acute Toxicity Assessment of Major Emissions On Selected Organisms

Experimental AnimalsThe test animals were selected based on numerical dominance and sensitivity. Thenumerically dominant species are the Mud Crab (Sessarma huzardi) and Earthworm(Eudrilus eugeniae), while the sensitive one is Termite (Macrotermes bellicosus). Thetest animals were collected from un-impacted sites because the tolerance level of theanimals in the contaminated field or site may have been increased by prolongedexposure to the pollutants over the years (Don Pedro et al, 2004).

AcclimatizationSessarma huzardi (Mud crab): During the acclimatization (5 days), 100 crabs were

kept in each of the four glass tanks measuring 76cm x 30cm x 30cm. All the tanks werehalf filled with water collected from the point of collection of the crabs, well aeratedwith aerators and muddy soil and leaves from the point of collection of the crabs wasadded to simulate their natural habitat. The crabs were fed with fermenting plantsobtained from the soil.

Eudrilus eugenia (Earth worm): The earth worm were acclimatized for five days.During acclimatization, 100 earthworms collected from zoological garden were kept ineach of the five round plastic bowls measuring 5000 cubic centimeters. Each bowl washalf filled with loamy soil containing decayed and decaying plant remains, collectedfrom the point of collection of the earth worm.

Macrotermes bellicosus (Termite): The termites were acclimatized for 1Hr in plasticcontainer measuring 12cm x 10cm x 10cm. Red mud and wet wood collected from thepoint of collection of the termites was used in the container to simulate their naturalhabitat and as food respectfully. Termites are eusocial insects- depend on othermembers for food. Taking the workers/solders from food will starve them to deathwithin two days.

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General Bioassay Procedures

Preparation of SubstrateFor all the test animals, six (6) clean glass tanks measuring 15cm x 15cm x 15cm,were used in two replicates.The substrate used for the crabs was mud obtained at the site where the crabs werecollected. It was standardized by sun-drying it for 3 days and removing solidparticulates, woods and planks. 2kg of the standardized substrate was placed and evenlydistributed at the bottom of each of the test and the control containers.For the earthworms and termites, 200g of the soil collected from the point of collectionof the earthworms and termites respectively was placed and evenly distributed at thebottom of each of the test containers.

Selection of Bioassay Animals

For crabs: Crabs within the range of 8g to 12g were placed into temporary containersfrom where they were randomly assigned to the experimental containers.

For Earthworm: Earthworms measuring 12cm – 15cm were randomly placed into theexperimental containers from temporary containers in such a way that each of them hadequal chance of being selected.

For Termites, similar sizes were used in order not to introduce bias.

A set of bioassay (e.g. for petrol against mud crabs), has six (6) set-ups, five (5)experimental and one (1) control (not treated with test compound). Mortality wasassessed once every 24 hours for 4 days. For termites, 24hrs acute toxicity test of petrol,diesel and kerosene against termites was carried out based on the procedure discussedabove. Mortality was assessed every hour for the first 6hrs and thereafter, once every 6hours for 24 hours.

Assessment of Quantal Response (Mortality)Death of test animal was taken to be the end result of the experiment. Death means nomovement of any part of the body on gentle prodding with a glass rod for the crabs andearthworms and camel hair brush for the termites after 2 to 3 minutes of observation.

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Chemical Analysis of Samples

Digestion of Animal SamplesWhole animal (Sessarma huzardi) from both sites (i.e. impacted and control sites) was

properly washed, brought out of their shells, weighed separately to obtain a uniformweight and dried. Each was grinded to powder in a mortar. A paste of each was madeby adding a little amount of distilled water. To each paste, 5ml of perchloric acid and5ml of nitric acid (HNO3) was added and boiled until digestion is completed. It wascooled for 5 minutes, filtered and distilled water was added to make-up to 100ml mark,after which each was analyzed for lead, copper and Zinc.

Digestion of Plant and water SamplesWhole plant from both sites was digested following similar procedure for the animalsabove. A 50ml each of water from both sites were transferred into 100ml digestionflask. The samples were digested with 5ml portion of concentrated nitric acid in a blockdigester. The resulting solutions were analyzed for lead, copper and zinc via AtomicAbsorption Spectrophotometer (AAS).

Digestion of Top-Soil and sedimentsTop-soil from both sites was digested by adding 2 molar Hcl to each 5g soil. Afterstirring for 6 hours on magnetic stirrer and filtered, distilled water was added to each tomake up to the 100ml mark in volumetric flask before analysis by AAS. Sedimentsfrom both sites were dried in the micro-wave oven, after which debris and otherunwanted materials were removed. It was properly grinded in a mortar and sieved,using 5mm sieve and 5g was weighed from each. A paste of each was prepared byadded little amount of distilled water and was digested with 5ml nitric acid. Distilledwater was then added to make up the 100ml mark before analysis using (AAS).

Digestion For Petrol, Kerosene and Diesel50ml portion of the petrol was evaporated on a water-bath. 10ml of the residue wasdigested with 5ml concentration nitric acid and was made up to 100ml calibration mark,before analysis by AAS. Similar procedures were followed for kerosene and dieselrespectively.

StatisticsThe statistics adopted is the probit analysis. This involves the transformation of thedose – Response data into probit values in order to determine: LC5, LC50 and LC95.

Toxicity Factor (TF) = 96hr LC50 value of other chemicals

96hr LC50 value of most toxic chemicals

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ResultsEmissions and PathwayEffluent discharge was not observed at the station. However, there were spills from

petrol, kerosene and diesel pumping machines as well as spent engine oil fromgenerator and the mechanic work-shop. After any rain, all these find their way to theaffected site behind the station through a channel (Plates 1and 2). Other emissions wereexhaust gas from the generator, which consisted of unburnt hydrocarbon, oxides ofNitrogen, Carbon and Sulphur and particulate matter. Also emitted were petrol andkerosene fumes (vapors). Solid wastes included empty cans and containers, unusedspare –parts and some municipal wastes from the food mart and mechanic workshop.

Plate 1: Showing the pathway throughwhich the emissions get into theenvironment

Plate 2: Showing the pathway of theemissions to impacted site.

The respondentsOut of the 50 respondents, 64% were Males and between the ages of 15 and 30(Fig. 2).Furthermore, 68% were not married (Fig. 3) and 94% claimed to be aware that therewas an AP filling station in Unilag (Fig. 4 and 5). Moreover, out of the 10 workersquestioned, 70% have worked there for 1-5years, while 10% worked for 11 years andabove (Fig. 6). 70% of these workers always feel tired at the end of the day after workwhile 10% feel pain while only 20% have headaches (Fig. 7).

Floral Species Diversity and Population DensityThe five major plant species identified at the study area were Solanium toruum,Laportea aestnans, Commeliara Spp, Cynodon diafylon and Amaranthus spinosus.

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Table 1 shows the distribution of each of the plant species between the impacted siteand the control site. The plant species are more abundant in the control than theimpacted site.

Faunal Species Diversity and Population DensityThe six major animal species identified during the faunal species diversity studyincludes earthworm (Eudrilus eugeniae), mud crab (Sessarma huzardi) praying mantis(Mantis religiosa), termites (Macrotermes bellicosus), ants and Slug (Ariolimaxcolumbianus). The animal species were more abundant in the control site than theimpacted site (Table 2).

Fig. 2Fig. 3

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Fig. 4Fig. 5

Fig. 6Fig. 7

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Table 1: The distribution of the major plant species between the impacted site andthe control site

S/N PLANT SPECIES IMPACTED SITE CONTROL SITE1 Solanium toruum 13 472 Laportea aestnans 11 1353 Commeliara spp 1139 56784 Cynodon diafylon 661 45295 Amaranthus spinosus 357 1309

Table 2: The distribution of the major animal species between the impacted siteand the control site

S/N COMMONNAME

ANIMAL SPECIES IMPACTEDSITE

CONTROLSITE

1 Earthworm Eudrilus eugeniae 7 182 Mud crab Sessarma huzardi 167 3793 Praying mantis Mantis religiosa 9 94 Termite Macrotermes bellicosus 0 5045 Slug Ariolimax columbianus 4 7

Toxicicity of Mudcrabs, Termites and Earthworms To Petrol, Kerosene and Diesel

The toxicity of petrol, Kerosene and Diesel on Termites, Mud Crabs and Earthworms

are shown in Table 3. Mud Crab is the most susceptible of the animals tested on Petrol,

Kerosene and Diesel. 0.20ml/L of Petrol gave 100% mortality of Mud Crabs and

Earthworm while 0.25ml/L concentration of Petrol and Kerosene gave 100% mortality

of Termites. On the other hand, Diesel at 0.25ml/L gave 70 and 90% mortality of

termites and Earthworms respectively.

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Table 3: Acute Toxicity Assessment of Termites, Mud Crab and Earthworm againstPetrol, Kerosene and Diesel

Conc.ml/l

Percentage Response%

Termites Mud Crabs Earthworm

Petrol Kerosene

Diesel Petrol Kerosene

Diesel Petrol Kerosene

Diesel

0.05 20 20 10 40 40 50 80 60 50

0.10 20 30 15 60 50 40 80 85 70

0.15 60 55 35 80 70 70 90 90 90

0.20 90 85 75 100 90 80 100 80 80

0.25 100 100 70 100 100 100 100 100 90

Control 0 0 0 0 0 0 0 0 0

Physico –Chemical Characteristics of Analysed SamplesThe analysis of petrol, diesel and kerosene which were the major emissions from thefilling station show the presence of measurable amount of heavy metals such as lead,iron, zinc and copper (Table 4). Petrol had the highest concentration of lead (79 ppm),followed by kerosene (54 ppm), and diesel (40ppm). Nickel was not detected in all thesamples.

Table 4: Composition of Petrol, Diesel and Kerosene

SAMPLESMETAL Petrol Kerosene Diesel

Sulphur 6ppm 1.6 ppm 2.3ppmCadmium 13ppm 11 ppm 9ppmZinc 58 ppm 69 ppm 51ppmCopper 43ppm 59ppm 43 ppmIron 55ppm 51ppm 69 ppmLead 79 ppm 54ppm 40ppmNickel N.D N.D N.DChromium 2.3pm 31ppm 27ppm

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Analyses of Heavy Metals In Water, Sediment, Plant, Animal, and Top-SoilAverage Concentration of Lead (Pb), Zinc (Zn) and Copper (Cu) in mg/L as contained

in water, sediment, plant, animal and top-soil were higher at impacted site than thecontrol sites (Figures 2, 3 and 4). In all, the highest quantity of these heavy metals wason top soil while the least were in the water analyzed. Lead was highest in the top soilin both impacted and control sites (Fig. 2) while on the other hand, Zinc was highest(29.59) in control than in impacted (28.51) topsoil and same with copper (14 and 11.98respectively) (Figs 3 and 4)

Figure 2 Average Concentrations of Lead (Pb) In Water, Sediments, Plant (AmaranthusSpinosus), Animal (Sessarma Huzardi) And Top Soil From Control and Impacted Site

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Figure 3 Average Concentrations of Zinc (Zn) In Water, Sediments, Plant (AmaranthusSpinosus), Animal (Mud Crab) and Top Soil from Control and Impacted Site.

Figure 4: Mean Concentrations of Copper (Cu) In Water, Sediments Plant, Animal(Sessarma huzardi) And Top Soil.

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Acute Toxicity of Major Emissions On Mud Crab (Sessarma huzardi), Earthworm(Eudrilus eugeniae), and Termite (Macrotermes bellicosus).

Tables 5, 6 and 7 show the relative acute toxicities of petrol, kerosene and diesel onMud Crab (Sessarma huzardi), Earthworm (Eudrilus euginiae) and Termite(Macrotermes bellicosus) respectively. The results show that the toxicity of petrol >kerosene > diesel. Petrol is the most toxic with LC50 of 0.275ml/L, followed bykerosene (1.645ml/L) and diesel (5.257ml/L) (Table 5). The Toxicity Factor (TF)revealed that petrol is 2.807 times more toxic than kerosene and 6.619 times more toxicthan diesel on earthworms (Table 6). Their toxicities on Termite (Macrotermesbellicosus) was petrol > kerosene > diesel, and petrol is 1.57 times more toxic than thediesel (Table 7). The LC50 values of the petrol, kerosene and diesel against Mud Crab(Sessarma huzardi) (0.3, 1.6, 5.2), Earthworm (Eudrilus euginiae) (0.9, 2.6 and 6.2) andTermite (Macrotermes bellicosus) (0.2, 0.2 and 0.3), are shown in (Figs 4, 5 and 6)respectively.

Table 5: Effects of Petrol, Kerosene and Diesel on Mud Crab (Sessarrma huzardi)

NB: C.L = 95% confidence Limit; S.E = Standard Error; T.F = Toxicity Factor; D.F = Degree of Freedom

Table 6: Effects of Petrol, Kerosene and Diesel on Earthworm (Eudrilus euginiae)

NB: C.L = 95% confidence Limit; S.E = Standard Error; T.F = Toxicity Factor; D.F = Degree of Freedom

TestCompound

Duration LC50

(Upper-Lower)C.L

Slope + S.E Probit Lineequation

D.F T.F

Petrol 96hr 0.275(0.372-0.143)

2.715 +0.847

Y=0.392+2.715x 3.0 1.00

Kerosene 96hr 1.645(2.524-0.647)

2.255 +0.821

Y=-1.742+2.255x 3.0 5.982

Diesel 96hr 5.257(7.202-2.259)

4.147 +1.486

Y=-5.933+4.147x 3.0 19.116

TestCompound

Duration LC50 (ml/L)(Upper-Lower)C.L

Slope +S.E

Probit Lineequation

D.F T.F

Petrol 96hr 0.949(1.895-0.011)

2.749 + 0.855 Y=1.030+2.749x 3.0 1.00

Kerosene 96hr 2.664(4.352-0.224)

4.107+ 0.993 Y=0.423+4.107x 3.0 2.807

Diesel 96hr 6.281(8.118-3.268)

4.707 + 1.591 Y=-1.064+4.707x 3.0 6.619

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Table 7: Effects of Petrol, Kerosene and Diesel on Termite (Macrotermes bellicosus)

NB: C.L = 95% confidence Limit; S.E = Standard Error; T.F = Toxicity Factor; D.F = Degree of Freedom

DISCUSSION

The post environmental impact assessment of University of Lagos AP filling stationshowed that the workers at the station were affected by the dispensing of the petroleumproducts (petrol, diesel and kerosene). 70% of the workers at the filling stationexhibited dizziness and have headache regularly. These are the major symptoms ofpetrol fumes inhalation. The workers are constantly exposed to sub-lethalconcentrations of the petrol fumes (Nwanjo and Ojiako, 2007).

Results from the analyses of heavy metals in water, sediment, plant, animal and top-soilshowed that the concentration of lead, copper and zinc in the water, sediment, plant,animal and top-soil from the study sites were not significantly different from those ofthe control sites, even though lead was observed to be higher in some parameters fromthe study sites than the control sites. This is because heavy metals are removed duringthe treatment of refined products as well as the replacement of lead (Pb) as anti-knockagent with BTEX (Uboh et al., 2008).

The result for acute toxicity testing for petrol, kerosene and diesel singly againstearthworm and crabs showed that petrol was more toxic, followed by kerosene, thendiesel.

Petrol is more toxic to the test organism because it is more volatile and can easilypenetrate the organisms than kerosene and diesel. The ability of a toxicant to penetratean organism is directly related to its bioavailability which is the amount of toxicantavailable to cause harm to the organism (Uboh et al., 2008).

TestCompound

Duration LC50

(Upper-Lower) C.LSlope +

S.EProbit Line

equationD.F T.F

Petrol 24hr 0.210(0.86 – 0.158

1.460+0.606

Y=2.154+0.525x 3 1

Kerosene 24hr 0.222(0.267- 0.179)

2.363+0.650

Y= 3.617 + 0.415x 3 1.06

Diesel 24hr 0.330(0.422 – 0.270)

3.171+0.669

Y= 1.526 + 0.379x 3 1.57

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Conclusion and Recommendation

From the results obtained during the course of this research, the inferences drawn arethat:

University of Lagos AP Filling Station is providing good services to theUniversity community.

The emissions from the activities of the filling Station have caused significantimpact on the abundance and diversity of the flora and fauna within the studylocations compared to the control.

In addition to these, recommendations are made that:

Petrol station attendants should put on personal protective equipments (Nosecovers, gloves, and fully fitted overalls) when at the filling station.

Environmental Impact Assessment (EIA) should be carried out before anyFilling Station is constructed in a sensitive environment.

Spent engine oil from workshops attached to filling stations should be properlydisposed.

Don Pedro, K. (2009). Man and the environmental crisis. University of Lagos Press,University of Lagos, Akoka. 375 pages.

Nwanjo, H.U., Ojiako, O.A. (2007). Investigation of the Potential Health Hazards ofPetrol Station Attendants in Owerri Nigeria. Journal of Applied Science andEnvironmental Management. 11 (2) 197 – 200.

Uboh, F.E., Akpanabiatu, M.I, Eteng, M.U., Ebong, P.E., Umoh, I.B. (2008).Toxicological effects of exposure to gasoline vapours in male andfemale rats. Internet Journal of Toxicology. 4(2)

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